I've been on some of these. They are more my style but are mainly gravel roads with some really nice scenery. I can't speak for all of this because I've only been on parts.
I did drive on the Amicalola Park Rd / FS 46 last weekend and it was still covered in snow (not sure if there was gravel under it or not). I got out to where there were no more tracks in the snow where I wanted to go (and got a little nervous since it was 6pm and I was by myself with my kids) and turned around. I think I was about where Old Bucktown and Nimblewill Gap split off. It was a nice drive but nothing challenging.
If you go a little further on Double Head Gap and take FS 58, there is a short hike on part of the Appalachian Trail to some neat falls called Long Creek Falls. Not usually many people back there so it's a fun drive on the FS to a nice hike.